Method for forming non-circular cartilage grafts

ABSTRACT

A technique for knee replacement surgery that allow for the removal of an oval oblong-shaped allograft bone and cartilage plug from a donor distal femur. The technique uses instruments including (i) sizing guides to match the recipient&#39;s femoral size and curvature to that of a donor femur (the sizing guides also acting as a wide pin placement template for the donor distal femur); (ii) osteotomes that cut the curved and straight portions of the implant shape (these may be disposable or reusable); and (iii) templates that fit over the guide pins and have openings to allow the osteotomes to cut the donor femur plug to the correct size, shape and depth. The instruments allow for a non-circular shape to be extracted from a donor femur for use in a bone-saving osteoarthritis distal femur resurfacing procedure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/180,949, filed Feb. 14, 2014, (now U.S. Pat. No. 9,216,022), whichclaims the benefit of U.S. Provisional Application No. 61/765,249, filedFeb. 15, 2013, the disclosures of which are incorporated by reference intheir entirety herein.

FIELD OF THE INVENTION

The present invention relates to the field of arthroscopic surgery and,more particularly, to methods of reconstructive knee surgery.

BACKGROUND OF THE INVENTION

Knee replacement surgery, also called knee arthroplasty, is routinelyconsidered for the treatment of osteoarthritis of the knee joint.Partial knee replacement surgery has generated significant interestbecause it entails a smaller incision and faster recovery thantraditional total joint replacement surgery.

When partial knee replacement is performed, the bone and cartilage onthe end of the femur and top of the tibia are removed. This is performedusing precise instruments to create exact surfaces to accommodate animplant. A knee replacement implant made of various biocompatiblematerials such as metal or plastic is then placed to function as a newknee joint.

The typical arthritic cartilage damage pattern is oval or oblong inshape; however, the current techniques only allow for a circularallograft bone plug implant, or for a metal or plastic oval or oblongimplant. Thus, the circular shape of the allograft implant does notcorrespond to the oblong or oval shape of the defect.

There is a need for a non-circular shape implant to be extracted from adonor femur for use in a bone-saving osteoarthritis distal femurresurfacing procedure. Also needed are instruments and techniques thatallow matching of the recipient's femoral size and curvature to that ofa donor femur (and to cut the donor femur cartilage plug to the correctsize, shape and depth).

SUMMARY OF THE INVENTION

The present invention provides techniques and instruments for kneereplacement surgery that allow for the removal of an oval oblong-shapedallograft bone and cartilage plug from a donor distal femur.

The invention provides (i) sizing guides to match the recipient'sfemoral size and curvature to that of a donor femur (the sizing guidesalso acting as a wide pin placement template for the donor distalfemur); (ii) osteotomes that cut the curved and straight portions of theimplant shape (these may be disposable or reusable); and (iii) templatesthat fit over the guide pins and have openings to allow the osteotomesto cut the donor femur plug to the correct size, shape and depth. Theseinstruments allow for a non-circular shape to be extracted from a donorfemur for use in a bone-saving osteoarthritis distal femur resurfacingprocedure.

The present invention also provides methods of forming non-circularcartilage grafts for the treatment of osteoarthritis of a knee joint byinter alia (i) using a 3D template to define the size and position ofthe harvest site (on the template, there are at least two holes forplacing alignment pins for subsequent steps—holes are outside theharvest site); (ii) inserting a guide over the drill pins placed in step(i) to cut or drill, for example; and (iii) placing a second guide tocreate more cuts if necessary.

Although the present invention is described below in connection with aknee procedure, the invention can also advantageously be used forsimilar procedures in joints other than the knee joint.

Other features and advantages of the present invention will becomeapparent from the following description of the invention which refers tothe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1(a) illustrates an expanded view of an oblong cutter system andinstrumentation (donor side) according to an exemplary embodiment of thepresent invention.

FIG. 1(b) illustrates a perspective view of the oblong cutter system ofFIG. 1(a) (in the assembled state).

FIG. 1(c) illustrates a cross-sectional enlarged view of the cutter andinserter of the oblong cutter system of FIG. 1(b).

FIGS. 1(d)-1(g) illustrate various views of the oblong cutter of thesystem of FIG. 1(a).

FIGS. 1(h)-1(k) illustrate various views of the cutter insert of thesystem of FIG. 1(a).

FIGS. 2(a)-2(c) illustrate cutting of the donor femur (donor side) withthe cutter of FIG. 1(a).

FIG. 3(a) illustrates an expanded view of an exemplary distractor systemused to remove the cutter and insert of the system of the presentinvention.

FIG. 3(b) illustrates another view of the exemplary distractor system ofFIG. 3(a) (in the assembled state).

FIG. 3(c) illustrates how the cutter is distracted from the femur withthe distractor system of FIG. 3(b).

FIG. 4(a) illustrates an expanded view of an exemplary oblong depthguide system (used with a sagittal saw guide) of the present invention.

FIG. 4(b) illustrates cutting of the femur (to an exemplary 5 mm minimumdepth) with the oblong depth guide system (used with a sagittal sawguide) of FIG. 4(a).

FIGS. 4(c)-4(h) illustrate details of the oblong depth guide of thesystem of FIG. 4(a).

FIGS. 5(a) and 5(b) illustrate depth cutting (donor side) with theoblong depth guide system of FIG. 4(b) and with an exemplary sagittalsaw guide of the present invention.

FIG. 5(c) illustrates depth cutting (donor side) with the oblong depthguide system and exemplary sagittal saw guide of FIG. 5(b) and with asaw blade.

FIGS. 5(d)-5(f) illustrate details of the sagittal saw guide of FIG.5(a).

FIG. 6 illustrates a donor implant of the present invention, formed withthe instrumentations and by the steps of FIGS. 1(a)-5(f).

FIGS. 7(a) and 7(b) illustrate various views of an exemplary recipientpin guide of the present invention (including a handle and a recipientguide) used to match the curvature of the recipient femur (recipientside), and according to an embodiment of the present invention.

FIGS. 7(c)-7(f) illustrate additional details of the recipient guide ofFIG. 7(a).

FIG. 8 illustrates the insertion of drill guide pins in the recipientguide of FIG. 17(a) (recipient side).

FIGS. 9(a) and 9(b) illustrate drilling of the ends of the oblong shaperecipient hole with the two drills (anterior drills).

FIGS. 10(a) and 10(b) illustrate drilling of the ends of the oblongshape recipient hole with the two drills (posterior drills).

FIGS. 10(c)-10(g) illustrate details of the recipient drill (withcutting flutes) of FIG. 10(b).

FIG. 11(a) illustrates a perspective view of an exemplary embodiment ofcleaning pliers of the present invention.

FIGS. 11(b) and 11(c) illustrate the pliers of FIG. 11(a) used to stripthe sides of the oblong recipient hole formed with the instruments ofFIGS. 9(a) and 9(b) and/or FIGS. 10(a) and 10(b).

FIG. 11(d) illustrates another schematic view of the cleaning pliers ofFIG. 11(a) (in the fully open position).

FIG. 11(e) illustrates an expanded view of the cleaning pliers of FIG.11(d).

FIG. 12(a) illustrates an exemplary donor implant in the proximity of arecipient femur with a recipient site formed according to the presentinvention.

FIG. 12(b) illustrates the complete final repair formed by pressing theexemplary donor implant of FIG. 6 into the recipient oblong hole of FIG.12(a).

FIG. 13(a) illustrates an expanded view of an oblong cutter system andinstrumentation (donor side) according to yet another exemplaryembodiment of the present invention.

FIG. 13(b) illustrates a perspective view of the oblong cutter system ofFIG. 13(a) (in the assembled state, i.e., with a cutter, guide pin,impactor (oblong cutter) and cutter insert).

FIG. 13(c) illustrates an enlarged view of the cutter of the oblongcutter system of FIG. 13(b).

FIG. 13(d) illustrates a perspective view of the oblong cutter system ofFIG. 13(a) (in the assembled state).

FIG. 14(a) illustrates an enlarged view of an exemplary distractor usedto remove the cutter and insert of the system of the present invention.

FIG. 14(b) illustrates the distractor of FIG. 14(a) used with a handleto remove the cutter insert from the cutter.

FIG. 14(c) illustrates the exemplary distractor system of FIG. 14(b)used to remove the cutter and insert of the system of the presentinvention.

FIG. 15(a) illustrates an assembled view of an exemplary oblong donordepth guide (used with a sagittal saw guide) of the present invention.

FIG. 15(b) illustrates an assembled view of the oblong donor depth guideof FIG. 15(a) assembled with a sagittal saw guide, and according to anembodiment of the present invention.

FIG. 15(c) illustrates the oblong donor depth guide assembled with thesagittal saw guide of FIG. 15(b), and further with an exemplary sawblade of the present invention.

FIG. 16(a) illustrates a perspective view of an exemplary recipientsizing device and recipient drill guide of the present invention (usedto match the curvature of the recipient femur (recipient side)), andaccording to yet another embodiment of the present invention.

FIG. 16(b) illustrates the recipient sizing device and recipient drillguide of FIG. 16(a) also shown with a detachable handle and drill guidepins.

FIG. 16(c) shows another view of the assembly of FIG. 16(b).

FIG. 17 illustrates a cannulated recipient drill shown with a drillguide pin and according to an exemplary embodiment of the presentinvention.

FIG. 17(a) shows an exemplary broach that can be used with the drillbits of the present invention.

FIG. 17(b) illustrates the broach of FIG. 17(a) used with an impactorand slipped over exemplary 4 mm drill bits.

FIGS. 18(a) and 18(b) illustrate views of a recipient cleaning pliers(in the closed and open positions, respectively) and used on therecipient side of the present invention (used to strip the sides of theoblong recipient hole formed with the instruments of FIGS. 13(a)-15(c),for example.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides instruments, systems and methods ofarthroscopically preparing a femur to accept an oval, oblong shapedimplant (a non-circular implant) from a donor femur plug, as part of amethod for treating osteoarthritis of a knee joint. The presentinvention also provides instruments, systems and methods of preparing anoval, oblong shaped implant (an allograft bone and cartilage plug)having a non-circular configuration/shape for treating osteoarthritis ofa joint (for example, in an osteoarthritis distal femur resurfacingprocedure).

The instruments and systems of the invention include at least one of thefollowing devices: (i) sizing guides to match the recipient's femoralsize and curvature to that of a donor femur (the sizing guides alsoacting as a wide pin placement template for the donor distal femur);(ii) osteotomes that cut the curved and straight portions of the implantshape (these may be disposable or reusable); and (iii) sizing templatesthat fit over the guide pins and have openings to allow the osteotomesto cut the donor femur plug to the correct size, shape and depth.

The instruments of the present invention allow for a non-circular shapeallograft (for example, an oval or oblong shaped allograft bone andcartilage plug) to be extracted from a donor femur for use in abone-saving osteoarthritis distal femur resurfacing procedure. In anexemplary embodiment, and as detailed below, the fixtures used in thedesign include: 1) sizing guides to match the recipient's femoral sizeand curvature to that of a donor femur, and the sizing guides also actas a guide pin placement template for the donor distal femur; 2)osteotomies that cut the curved and straight portions of the implantshape; these may be disposable or reusable; and 3) templates the fitover the guide pins and have openings to allow the osteotomes to cut thedonor femur plug to the correct size, shape and depth.

As detailed below, the invention allows for a non-circular shape to beextracted from a donor femur for use in a bone-saving osteoarthritisdistal femur resurfacing procedure. The typical arthritic cartilagedamage pattern is oval or oblong in shape, and current art only allowsfor a circular allograft bone plug implant or for a metal or plasticoval or oblong implant. Thus, the invention allows for the combinationof the correct implant shape with allograft donor materials. Thesingle-piece, allograft plugs of the present invention consistessentially of cartilage and bone, have a non-circular shape (oval oroblong or combination thereof) and have a height as small as about 5 mm.

Referring now to the drawings, where like elements are designated bylike reference numerals, FIGS. 1(a)-18(b) illustrate exemplary surgicalinstruments, kits and systems of the present invention, for methods ofresurfacing a distal femur (for exemplary treatment of osteoarthritis ofa knee joint). Exemplary repair 100 is shown in FIG. 12(b), which showsdonor implant 150 with a non-circular configuration (shape) of thepresent invention secured to a femoral recipient site 166 for receivingthe donor implant 150.

As detailed below, the donor implant 150 of the present invention isformed by employing specific instrumentation and by a sequence ofspecific steps (i.e., providing an impactor to impact a cutter assemblywith a cutter with guide pin and a cutter insert; providing a distractorto remove the cutter insert from the cutter; and providing a donor depthguide and saw guide assembly with a sagittal saw blade to cut the boneblock and release the donor implant).

As detailed below, the femoral recipient site 166 of the presentinvention may be formed by employing specific instrumentation and by asequence of specific steps (i.e., providing a sizing device andrecipient drill guide with a detachable handle and drill guide pins;providing a broach with an impactor handle and drill bits to form anoblong hole in the recipient femur; providing a recipient cleaningpliers to clean the sides of the oblong hole and match the curvature ofthe donor implant.

FIGS. 1(a)-12(b) illustrate instruments and methods employed forallograft reconstruction according to an exemplary embodiment of thepresent invention. A non-circular shaped implant (an oval oblong shapedand cartilage plug) is extracted from a donor femur 90 for use in aresurfacing procedure by using specialized instruments and procedures.FIGS. 1(a)-5(f) illustrate the donor side instrumentation for obtainingcut donor implant 150 (curved and oblong) of the present invention (alsoshown in FIG. 6). FIGS. 7(a)-11(e) illustrate the recipient sideinstrumentation for forming a recipient site to secure cut donor implant150 (curved and oblong) therein.

FIGS. 1(a)-1(c) illustrate various elements of oblong cutter system 70(first cutter assembly) and instrumentation of the present inventionused on the donor side. Oblong cutter system 70 includes handle 71,impactor 72, oblong cutter 75 and cutter insert 77. FIGS. 1(d)-1(g)illustrate details and various views of the oblong cutter 75 having agenerally oval configuration as seen from the bottom view, for example.Wall 76 has two curved portions 76 a adjacent and in contact with twostraight portions 76 b. Wall 76 (that has a continuous oval perimeter)has a height “h” (FIG. 1(d)). Threaded cylindrical portion 76 c extendsin a direction about parallel to that of the direction of wall 76.

FIGS. 1(h)-1(k) illustrate details and various views of the cutterinsert 77 of cutter system 70. Cutter insert 77 has an outer shape andconfiguration that resembles the shape and configuration of the innerpart of the oblong cutter 75 (i.e., of the region located within thecontinuous wall 76) so that, when inserted into the cutter 75, theinsert 77 tightly engages and fits within the inside of the cutter 75(i.e., within the inner recess/cannulation of the cutter). Concaveregion 77 a is designed to match and contact the femoral cortex, asshown in FIGS. 1(h) and 1(k), for example. When inserted within thecutter 75, the insert 77 engages the inner region of the wall 76 of thecutter 75, as detailed in FIG. 1(c).

FIGS. 2(a)-2(c) illustrates cutting of the donor femur 90 (donor side)with the system 70 including oblong cutter 75 (first cutter), insert 77and impactor 72. The curved cutting edge of cutter 75 is aligned to thesurface of the femur 90 (and inserted to hard depth stop) to cut femur90 a length L (FIG. 2(c)) from the femoral cortex, cutting through thecartilage and bone. Cutter 95 is impacted into femur 90 to form a firstcut having an oval or oblong configuration (cross-section andperimeter).

FIGS. 3(a)-3(c) illustrate how the cutter 75 is distracted from thefemur 90 with specific instrumentation (on the donor side), i.e., with adistractor assembly 80 comprising a handle 81 and a distractor 88. Thecutter is distracted/removed from the femur by the following exemplarysteps: remove impactor 72 and handle 71; assemble distractor 88 with ahandle 81; thread distractor 88 into cutter 75; after the distractor 88makes contact with the inserter 77, the inserter will be pushed to thecartilage surface; continuing to advance the distractor 88 will resultin the cutter 75 backing out of the femur 90. FIG. 3(c) shows the cutter75 and inserter 77 about completely removed from the femur 90 leavingfemoral cut 91 having an oval or oblong cross-section.

FIGS. 3(d)-3(f) illustrate additional details and views of the threadeddistractor 88 of the distractor assembly 80 of FIG. 3(a).

FIGS. 4(a) and 4(b) illustrate cutting femur 90 to a 5 mm minimum depthwith oblong depth guide system 70 a (second cutter assembly) andsagittal saw guide instrumentation (donor side). Oblong depth guidesystem 70 a includes handle 71 a, oblong depth guide 75 a (secondcutter) and insert 77 a. Details of oblong depth guide 75 a areillustrated in FIGS. 4(c)-4(h). Oblong depth guide 75 a is about similarto the cutter 75 detailed above but differs in that the depth guide 75 ais provided with slots 79 to allow a saw 85 a to cut the femur to thedesired depth, and as detailed below (i.e., in a second direction whichis about perpendicular to the direction of the first cut). For example,depth guide 75 a is also provided with a generally oval configuration asseen from the bottom view. Wall 76′ has two curved portions 76 a′adjacent and in contact with two straight portions 76 b′. Wall 76′ (thathas a continuous oval perimeter) has a height “h” (FIG. 4(d)). Threadedcylindrical portion 76 c′ extends in a direction about parallel to thatof the direction of wall 76′.

FIGS. 5(a)-5(c) illustrate depth cutting of the femur 90 by engagingguide 85 (third cutter) with depth guide 75 a through arm 86 and by thefollowing exemplary steps: insert oblong depth guide 75 a to hard stop(the thin walled part will slip into the previously made cut); removeimpactor handle; slip sagittal saw guide 85 over the oblong depth guide75 a; use a sagittal saw 85 a (blade 85 a) to cut the medial side of thedonor femur 90; once again, use the distractor 88 (FIGS. 3(a)-3(f) toremove the oblong depth guide 75 a against the inserter (because of theslip fit, this step may not be necessary); remove all instrumentation toreveal the implant 150 (FIG. 6). FIGS. 5(d)-5(f) illustrate additionaldetails and views of the sagittal saw depth guide 85 of FIGS. 5(a)-5(c).

FIG. 6 illustrates donor implant 150 with a non-circular configuration(shape) of the present invention, having sidewalls 51 with an outersurface having a smooth configuration and defining a perimeter with agenerally oblong and curved configuration (obtained by the first cutsformed with the cutter 75 and depth cutter 75 a), a first surface 52having a generally flat profile (obtained by the second cut formed withthe sagittal saw blade 85 a), and an opposing second surface 53 havingthe shape of the femoral cortex of the donor femur 90 (i.e., having aconfiguration that matches the surface contour and curvature of thedefect region of a recipient femur). Donor implant 150 has across-section that is oval or oblong, or combination of oval and oblong,as viewed when taking a cut perpendicular to longitudinal axis 51 a.

FIGS. 7(a)-11(e) illustrate the recipient side instrumentation forforming a recipient site to secure cut donor implant 150 (curved andoblong) therein. The recipient site (a femoral recipient site) is formedby methods of the present invention, as detailed below, and allows theas-formed recipient site to receive the exemplary donor implant 150 ofFIG. 6.

FIGS. 7(a) and 7(b) illustrate a recipient pin guide 110 used to matchthe curvature of recipient femur 95 (the femur on the recipient side).Recipient pin guide 110 comprises a handle 111 attached to a recipientguide 115. Details and additional views of the recipient guide 115 areshown in FIGS. 7(c)-7(f). Recipient guide 115 is provided with a bodyand two openings 116 to allow a plurality of drill guide pins 120 topass therethrough. FIG. 8 illustrates the insertion of drill guide pins120 (on the recipient side) with the recipient pin guide 110. Thecontour (perimeter) of the body of the recipient guide 115 resemblesthat of the outer perimeter of the donor implant 150.

FIGS. 9(a) and 9(b) illustrate the step of drilling the two ends of theoblong shape (that would define the shape of the recipient site in femur95) with the two drills 120 (an anterior drilling procedure).

FIGS. 10(a) and 10(b) illustrate the step of drilling the ends of theoblong shape with the drills 120 (in a posterior drillingprocedure—posterior drill). Recipient drill 130 with cutting flutes 133is shown in more details in FIGS. 10(c)-10(g).

FIG. 11(a) illustrates an exemplary cleaning instrument 140 (cleaningpliers 140) of the present invention. The sides of the oblong hole arestripped (cleaned) with cleaning pliers 140 to form a recipient hole orthrough 166, as shown in FIGS. 11(b) and 11(c). Details and an explodedview of the cleaning pliers 140 are shown in FIGS. 11(d) and 11(e). Thecleaning pliers 140 includes a plier handle 1, two anterior jaws 2, twoshort cross pins 3, and four long cross pins 4.

To assemble the instrument 140, the following steps may be followed:orient both items 1 as shown and insert both items 3 through the centerhole of each side, such that the hollow end faces outward; pin hollowend of items 3 to secure it in place; slip 2 items 4 into the back holesin both items 1 (orient heads of long pins on same side of assembly);pin hollow end of items 4 to secure in place; slip 1 item 2 over loweritem 4 and align with front hole in item 1; slip item 4 through items 1and 2; pin hollow end of item 4 to secure it in place; repeat steps 5-7for the upper item 4 to secure it in place; and lubricate and verifyactuation of assembly.

FIGS. 12(a) and 12(b) illustrate the completion of the repair 100 of thepresent invention, by pressing the donor implant 150 into the recipientoblong hole 166 of recipient femur 95.

FIGS. 13(a)-18(b) illustrate another embodiment of the instrumentationof the present invention. FIGS. 13(a)-15(c) illustrate the donor sideinstrumentation for obtaining cut donor implant 150 (curved and oblong)of the present invention. FIGS. 16(a)-18(b) illustrate the recipientside instrumentation for forming a recipient site to secure cut donorimplant 150 (curved and oblong) therein. The instruments of thisembodiment differ, however, from the instruments of the first embodimentin slight changes both in the design and configuration of some of theinstruments, and also in the sequence of steps employed.

FIGS. 13(a)-13(d) illustrate various elements of oblong cutter system170 (first cutter assembly) that includes handle 171, impactor 172,oblong cutter 175, cutter insert 177 and guide pin 160. Oblong cutter175 has a generally oval configuration as seen from the bottom view, forexample (the configuration being about similar to that of the cutter 75detailed above). System 170 is also provided with guide pin 160 thatallows pin 161 to pass through a cannulation of the guide pin, as shownin FIG. 13(d), for example. Cutter insert 177 is also similar to thecutter insert 77 detailed above (i.e., configured to be received withinthe cutter 175).

FIG. 14(a) shows an enlarged view of exemplary distractor 188 (similarto distractor 88 detailed above) used to remove the cutter and insert ofthe system 170 of the present invention. Handle 82 (FIG. 14(b)) isattached to the distractor to remove the cutter insert 177 from thecutter 175 (FIG. 14(c)).

FIGS. 15(a)-15(c) illustrate an exemplary oblong donor depth guide 175 aused with a sagittal saw guide 185 of the present invention. Saw blade185 a is employed with the saw guide 185 to cut the donor allograftcartilage and bone plug 150 by conducting a cutting motion in adirection about perpendicular to that formed by the oblong cutter 175,and as detailed above with reference to the second exemplary embodimentof the present invention.

FIGS. 16(a)-18(b) illustrate instruments and systems on the recipientside, i.e., to form recipient site 166 of FIG. 22(a). FIGS. 16(a)-16(c)show sizing device 215 and recipient drill guide 216 (also shown with adetachable handle 211 and 4 mm drill guide pins). FIG. 17 shows acannulated recipient drill 230 with an exemplary 4 mm guide pin 220.

FIGS. 17(a) and 17(b) show a broach 235 (also shown with impactor handleand slipped over 4 mm drill bits). FIGS. 18(a) and 18(b) show recipientcleaning pliers 140 which are similar to pliers 140 of FIGS.11(a)-11(d). Cleaning pliers 140 are used to strip the sides of theoblong recipient hole 266 formed with the instruments of the presentinvention.

The present invention provides techniques and instruments for allograftfemoral total knee reconstruction. A non-circular shaped allograft isextracted from a donor femur with specific instruments (and by specificmethods) and then inserted into a recipient femur having a correspondingnon-circular recipient site configuration. The methods of the presentinvention allow restoration of both the damaged cartilage and bone thatoccur in typical arthritic affections by providing completed allograftimplants that are cut to a depth of about 5 mm minimum depth withspecialized instruments (compared to current instruments that allowdepth of only 6.35 mm at the narrowest portion regardless of the size ofthe femur).

While the present invention is described herein with reference toillustrative embodiments for particular applications, it should beunderstood that the invention is not limited thereto. Those havingordinary skill in the art and access to the teachings provided hereinwill recognize additional modifications, applications, embodiments andsubstitution of equivalents all falling within the scope of theinvention.

What is claimed is:
 1. A method of forming an allograft plug comprisingcutting a donor femur in a first direction with a first cutter assembly;and cutting the donor femur in a second direction with a second cutterassembly, the second direction being about perpendicular to the firstdirection, wherein the allograft plug is a single piece and has anon-circular shape.
 2. The method of claim 1, wherein the allograft plugcomprises bone and cartilage.
 3. The method of claim 1, wherein theallograft plug consists essentially of bone and cartilage.
 4. The methodof claim 1, wherein the non-circular shape is oval oblong.
 5. The methodof claim 1, wherein the first cutter assembly or the second cutterassembly comprises an oblong cutter.
 6. The method of claim 1, whereinthe first cutter assembly or the second cutter assembly comprises acutter insert.
 7. The method of claim 6, wherein the cutter insert hasan outer shape and configuration that resembles a shape andconfiguration of an inner part of an oblong cutter.
 8. The method ofclaim 6, wherein the cutter insert comprises a concave region.
 9. Themethod of claim 1, wherein the first cutter assembly or the secondcutter assembly comprises a guide pin.
 10. The method of claim 9,wherein the guide pin allows a pin to pass through a cannulation. 11.The method of claim 1 further comprising depth cutting.
 12. The methodof claim 11, wherein the depth cutting comprises engaging the femur witha third cutter with a depth guide.
 13. The method of claim 1, whereinthe cutting the donor femur in the first direction or a second directioncomprises cutting with a sagittal saw.
 14. The method of claim 1,wherein the allograft plug comprises a surface contour and curvature ofa defect region of a recipient femur.